Mesenchymal stem cells (MSCs) have been utilized to rescue disease phenotypes in genetic disorders, to direct healing after traumatic injury and to suppress the immune response in a variety of autoimmune disorders. We have demonstrated that corneal UMSC (umbilical mesenchymal stem cells) transplantation rescues the cloudy, thin cornea stroma of lumican knockout (Lum-/-) mice. Thus, transplantation of UMSC can be beneficial to ameliorate corneal pathology caused by genetic defects. UMSC can suppress host inflammation and immune responses and have been used in solid organ co-transplantation to improve graft success rates. Our preliminary studies have showed that intrastromal UMSC transplantation allow the alkali- burned corneas to regain transparency, to prevent the formation retro-corneal membrane when UMSC are transplanted into the anterior chamber. Our hypothesis is that modulation of inflammation and suppression of autoimmunity by UMSC transplantation are beneficial for regeneration/repair and survival of progenitor/stem cells in traumatized corneas. The specific aims will determine the efficacy of utilizing UMSCs for the treatment of three models of human corneal dysfunction: trauma, limbal deficiency due to persistent inflammation and/or immune disorders, and genetic disease. Specific Aim 1: To examine the efficacy of UMSC in treating traumatized mouse corneas. The hypothesis is that UMSC will modulate the inflammatory response and facilitate regeneration; Specific Aim 2: To examine the efficacy of UMSC transplantation in treating limbal stem cell deficiency. The hypothesis is persistent inflammation leading to progenitor/stem cell deficiency can be ameliorated by UMSC transplantation; Specific Aim 3: To determine whether UMSC transplantation can restore function in a corneal stroma with a congenital defect. The hypothesis is that UMSC will remodel and repair stromal defects resulting from mutant proteins in genetic disease thereby restoring function. The outcome of our proposed studies will lend support to the notion that UMSC transplantation can serve as an alternative treatment in lieu of penetrating keratoplasty for cornea dysfunction caused by trauma and mutation by the preservation of progenitor/stem cells in persistent inflammation and/or immune disorders. Thus, the UMSC transplantation can be a potential treating regimen for dry eyes, Sjogren and Stevens-Johnson syndromes that are characterized by persistent inflammation and autoimmune disorder.